This is the last book of Nicolas de Malebranche (1638-1715), the famous Cartesian philosopher. It was written as a retort to Laurent Boursiers De lAction de Dieu sur les créatures. Boursier maintained that Malebranches philosophy of occasionalism leads naturally to the Thomistic position that God determines our action by means of a physical premotion. Malebranche responded that our free action involves a consent that God does not determine.